1. Field of the Invention
The present invention is broadly concerned with decontamination products useful for the neutralization of chemical and biological compounds or agents, such as chemical weapon (CW) and biological weapon (BW) agents and environmental contaminants such as toxic industrial chemicals (TIC""s) and toxic industrial materials (TIM""s) and biologicals such as spores, bacteria, fungi, molds and viruses. More particularly, the invention is concerned with such products which may be in liquid form as sprayable or foamable products for example, together with corresponding application methods and devices permitting area decontamination. The decontamination products advantageously include a quantity of nanoscale metal particles (e.g., nanoparticulate metal oxides, hydroxides and mixtures thereof), a biocide and a liquid carrier for the nanoparticles and biocide.
2. Description of the Prior Art
Governments around the world have become increasingly concerned about the effects of chemical and/or biological warfare agents, industrial chemicals and other types of hazardous substances, particularly in light of the recent rise in terrorism. The potentially catastrophic results which could ensue in high density population centers subjected to such agents are well known to disaster experts. In addition concerns over environmental contaminants, chemical and biological, including industrial chemicals, raise concerns over public safety. A number of proposals have been adopted for dealing with CW, BW, industrial chemicals, environmental contaminants and similar substances.
There are currently two general types of decontamination methods for biological agents, namely chemical disinfection and physical decontamination. Chemical disinfectants such as hypochlorite solutions are useful but are corrosive to most metals and fabrics, and to human skin. Liquid-like foam disinfectants have also been used, and generally require water and pressurized gases for efficient application. Physical decontamination usually involves dry heat up to 160xc2x0 C. for 2 hours or steam or super-heated steam for about 20 minutes. Sometimes UV light can be used effectively, but it is generally difficult to implement in actual practice. Techniques used for decontamination of areas subjected to chemical warfare agents, TICs and TIMs are more varied, and depend principally upon the nature of the agent in question.
U.S. Pat. No. 5,914,436 describes methods for the destruction of unwanted compounds such as chlorocarbons, chlorofluorocarbons and PCBs, making use of metal oxide composites as adsorbents. Also, U.S. Pat. No. 6,057,488 describes the use of metal oxide nanoparticles for the destructive adsorption of biological and chemical contaminants, including biological and chemical warfare agents and environmental contaminants. However, these references do not describe techniques for the rapid use of metal oxides in emergency-type situations.
Sandia National Laboratories has recently developed a foam decontamination product referred to as xe2x80x9cSandia Decon Formulationxe2x80x9d and includes solubilizing compounds such as cationic surfactants and hydrotropes together with reactive compound(s) such as nucleophilic and oxidizing compounds. The Sandia foam products are available from EnviroFoam Technologies of Huntsville, Ala., and Modec, Inc. of Denver, Colo., and are described in PCT Publication WO 02/02192 published Jan. 10, 2002 and incorporated by reference herein. However, the Sandia Decon Formulation does not make use of reactive metal oxide or hydroxide nanoparticles.
The present invention overcomes the problems outlined above and provides improved decontamination products adapted for rapid, large-scale area decontamination by neutralization of a variety of undesirable toxants, i.e., any chemical or biological compound, constituent, species or agent that through its chemical or biological action can cause death, temporary or permanent incapacitation or harm to humans or animals. Neutralization refers to the mitigation, detoxification, decontamination or other destruction of toxants to the extent that they no longer cause significant adverse effects.
Broadly speaking, the decontamination products of the invention include a quantity of nanoparticles selected from the group consisting of metal oxides, metal hydroxides and mixtures thereof, one or more biocides and a liquid carrier for the nanoparticles and biocide. The preferred products are formulated for application as liquids, sprays, fogs, aerosols, pastes, gels and foams, depending upon the desired mode of application and end use.
The nanoparticles are preferably selected from the group consisting of the alkali metal, alkaline earth metal, transition metal, actinide and lanthanide oxides and hydroxides, and mixtures thereof, more preferably, the nanoparticles are selected from the group consisting of Al, Ca, Ce, Mg, Sn, Sr. Ti and Zn and mixtures thereof. Particularly preferred nanoparticles, from the standpoints of cost and ease of preparation as well as effectiveness, are selected from the group consisting of Al, Ca, Mg, Ti and Zn. The nanoparticles most useful in the invention comprise single crystallites or polycrystallite aggregations having an average crystallite size of up to about 20 nm, and more preferably from about 2-10 nm. Such crystallites or polycrystallate aggregates also advantageously have a BET surface area of at least about 15 m2/g., and more preferably from about 20-1200 m2/g, most preferably from about 90-600 m2/g.
A virtually unlimited number of biocides in addition to the nanoparticles can be used in the context of the invention, for example biocides selected from the group individually or mixtures thereof consisting of biocidally active peroxides including hydrogen peroxide, mono- and polyfunctional alcohols, aldehydes, acids, ozone, naphtha compounds and compounds containing an alkali metal, a transition metal, a Group III or Group IV metal, a sulfur, a nitrogen, or a halogen atom. Particular biocides are those selected from the group consisting of formaldehyde, glutaraldehyde, peracetic acid, the alkali metal hypochlorites, quaternary ammonium compounds, 2-amino-2-methyl-1-propanol, cetyltrimethylammonium bromide, cetylpyridinium chloride, 2,4,4-trichloro-2-hydroxydiphenylether, 1-(4-chlorophenyl)-3-(3,4-dichlorophenyl) urea, zinc oxide, zinc ricinoleate, pentachlorophenol, copper naphthenate, tributyltin oxide, dichlorophen, p-nitrophenol, p-chloro-m-xylenol, beta-naphthol, 2,3,5,6-tetrachloro-4-(methyl sulfonyl)-pyridine, salicylanilide, bromoacetic acid, alkyl quaternary ammonium acetate, sodium ethyl mercuric thiosalicylate, sodium orthophenyl phenate, n-alkyl (C12 to C18) dimethyl benzyl ammonium chloride, the organoborates, 2,2-(1-methyltrimethylenedioxy)-bis-(4-methyl-1,3,2-dioxaborinane), 2,2-oxybis(4,4,6-trimethyl)-1,3,2-dioxaborinane, ethylene glycol monomethyl ether, parahydroxy benzoates, organic boron compounds, 8-hydroxyquinoline, sodium pentachlorophenate, dimethylethylalkylbenzyl ammonium chloride, alkylammonium salts of 2-pyridinethiol-1-oxide, 1,3,5-triethylhexahydro-1,3,5-triazine, strontium chromate, the halogenated phenols, 2-bromo-4-phenylphenol, the silver salts such as silver nitrate, silver chloride, silver oxide and elemental silver, the organic peroxides, silver sulfadiazine, sodium dichloro-s-triazinetrione, dyhydrate-4-chloro-2-cyclo-hexylphenol, 2-chloro-4-nitrophenol, the substituted paraffins, 3-chloro-3-nitro-2-butanol, 2-chloro-2-nitro-1-butanol stearate, 2-chloro-2-nitrobutyl acetate, 4-chloro-4-nitro-3-hexanol, 1-chloro-1-nitro-1-propanol, 2-chloro-2-nitro-1-propanol, triethyltin chloride, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,2-thiobis(3,4,6-trichlorophenol), 1,3-dichloro-5,5-dimethylhydantoin, tris(hydoxy-methyl)nitromethane, the nitroparaffins. 2-nitro-2-ethyl-1,3-propanediol dipropionate, 2-nitro-2-ethyl-1,3-propanediol, 2-nitro-2-methyl-1,3-propanediol, hexahydro-1,3,5-tris(2-hydroxy-ethyl)-s-triazine, 1,3,5-tris(tetrahydro-2-furanyl)-methyl-hexahydro-s-triazine, methyl bisthiocyanate, 2,2-dibromo-3-nitrilopropionamide, xcex2-bromo-xcex2-nitrostyrene, fluorinated compounds, N-ethyl-N-methyl-4-(trifluoromethyl)-2-(3,4-dimethoxyphenyl) benzamide, pentachlorophenol, dichlorophene, orthophenyl phenol, di-bicyclo-(3,1,1 or 2,2,1)-heptyl and di-bicyclo-(3,1,1 or 2,2,1)-heptenyl polyamines.
The liquid carriers for the nanoparticles and biocide are generally selected from the group consisting of solvents (both aqueous and non-aqueous), dispersants and emulsion systems and combinations thereof. The solvents are generally capable of solvating the biocide fraction of the products, but in many instances are incapable of solvating the nanoparticles, which may also incorporate the antimicrobial agent on the nanoparticle. As the name implies, the dispersants are used to create dispersions or suspensions which are not true solutions. The emulsion systems may be oil-in-water or water-in-oil systems and generally are made up of respective quantities of oil, water and surfactant. The surfactants may be of nonionic, cationic or anionic nature, and the oils may be natural or synthetic.
Generally speaking, the nanoparticle fraction of the products should be present at a level of from about 0.1 to 40% by weight, and more preferably from about 1 to 10% by weight; the biocide fraction should be at a level of from about 0.001 to 10% by weight, and more preferably from about 0.01 to 5% by weight; and the liquid carrier fraction should be present at a level of from about 50 to 99.9% by weight, and more preferably from about 85 to 99% by weight.
In many instances, preparation of the products of the invention involves direct addition of the selected nanoparticles into the liquid carrier, often with supplemental mixing to insure homogeneity. Again depending upon the selected carrier it may be necessary to heat the system to facilitate incorporation of the nanoparticles and/or biocide(s). In the case of emulsions the chosen surfactant(s) may be mixed with the oil fraction and nanoparticles, followed by heating and addition of water, or can be mixed with the water. The formulation is preferably a single solution, but the individual components of the solution may be packaged separately.
The preferred products of the invention, depending upon the type and quantity of reactive nanoparticles and biocide(s) selected, have an extremely broad effectiveness against toxants. Such would include CW agents, BW agents, TICs and TIMs (e.g., sarin, soman, VX, mustard, spore forming bacterium such as anthrax, vegetative bacterium such as plague and cholera, virus such as smallpox, yellow fever, fungi and molds, and bacterial toxins such as botulism, ricin and those from fungi and molds). Additionally, chemical toxants include but are not limited to o-alkyl phosphonofluoridates, such as sarin and soman, o-alkyl phosphoramidocyanidates, such as tabun, o-alkyl, s-2-dialkyl aminoethyl alkylphosphonothiolates and corresponding alkylated or protonated salts, such as VX, mustard compounds, including 2-chloroethylchloromethylsulfide, bis(2-chloroethyl)sulfide, bis(2-chloroethylthio)methane, 1,2-bis(2-chloroethylthio)ethane, 1,3-bis(2-chloroethylthio)-n-propane, 1,4-bis(2-chloroethylthio)-n-butane, 1,5-bis(2-chloroethylthio)-n-pentane, bis(2-chloroethylthiomethyl)ether, and bis(2-chloroethylthioethyl)ether, Lewisites, including 2-chlorovinyldichloroarsine, bis(2-chlorovinyl)chloroarsine, tris(2-chlorovinyl)arsine, bis(2-chloroethyl)ethylamine, and bis(2-chloroethyl)methylamine, saxitoxin, ricin, alkyl phosphonyldifluoride, alkyl phosphonites, chlorosarin, chlorosoman, amiton, 1,1,3,3,3,-pentafluoro-2-(trifluoromethyl)-1-propene, 3-quinuclidinyl benzilate, methylphosphonyl dichloride, dimethyl methylphosphonate, dialkyl phosphoramidic dihalides, alkyl phosphoramidates, arsenic trichloride, diphenyl hydroxyacetic acid, quinuclidin-3-ol, dialkyl aminoethyl-2-chlorides, dialkyl aminoethane-2-ols, dialkyl aminoethane-2-thiols, thiodiglycols, pinacolyl alcohols, phosgene, cyanogen chloride, hydrogen cyanide, chloropicrin, phosphorous oxychloride, phosphorous trichloride, phosphorus pentachloride, alkyl phosphorous oxychloride, alkyl phosphites, phosphorous trichloride, phosphorus pentachloride, alkyl phosphites, sulfur monochloride, sulfur dichloride, thionyl chloride, acetaldehyde, acetone, acrolein, acrylamide, acrylic acid, acrylonitrile, aldrin/dieldrin, aluminum, americium, ammonia, aniline, antimony, arsenic, asbestos, atrazine, barium, benzene, benzidine, 2,3-benzofuran, beryllium, 1,1xe2x80x2-biphenyl, bis(2-chloroethyl)ether, bis(chloromethyl)ether, boron, bromodichloromethane, bromoform, bromomethane, 1,3-butadiene, 1-butanol, 2-butanone, 2-butoxyethanol, butraldehyde, cadmium, carbon disulfide, carbon tetrachloride, carbonyl sulfide, cesium, chlordane, chlordecone and mirex, chlorfenvinphos, chlorinated dibenzo-p-dioxins (CDDs), chlorine, chlorobenzene, chlorodibenzofurans (CDFs), chloroethane, chloroform, chloromethane, chlorophenols, chlorpyrifos, chromium, cobalt, copper, crankcase oil, creosote, cresols, cyanide, cyclohexane, DDT, DDE, DDD, DEHP, di(2-ethylhexyl)phthalate, diazinon, dibromochloropropane, 1,2-dibromoethane, 1,4-dichlorobenzene, 3,3xe2x80x2-dichlorobenzidine, 1,1-dichloroethane, 1,2-dichloroethane, 1,1-dichloroethene, 1,2-dichloroethene, 1,2-dichloropropane, 1,3-dichloropropene, dichlorvos, diethyl phthalate, diisopropyl methylphosphonate, di-n-butylphtalate, 1,3-dinitrobenzene, dinitrocresols, dinitrophenols, 2,4- and 2,6-dinitrotoluene, 1,2-diphenylhydrazine, di-n-octylphthalate (DNOP), 1,4-dioxane, dioxins, disulfoton, endosulfan, endrin, ethion, ethylbenzene, ethylene oxide, ethylene glycol, fluorides, formaldehyde, freon 113, fuel oils, gasoline, heptachlor and heptachlor epoxide, hexachlorobenzene, hexachlorobutadiene, hexachlorocyclohexane, hexachlorocyclopentadiene, hexachloroethane, hexamethylene diisocyanate, hexane, 2-hexanone, HMX (octogen), hydraulic fluids, hydrazines, hydrogen sulfide, iodine, isophorone, jet fuels, kerosene, lead, malathion, manganese, MBOCA, mercury, methanol, methoxychlor, 2-methoxyethanol, methyl ethyl ketone, methyl isobutyl ketone, methyl mercaptan, methyl parathion, methyl t-butyl ether, methylchloroform, methylene chloride, methylenedianiline, methyl methacrylate, methyl-tert-butyl ether, mirex and chlordecone, mustard gas, N-nitrosodimethylamine, N-nitrosodiphenylamine, N-nitrosodi-n-propylamine, naphthalene, nickel, nitrobenzene, nitrophenols, otto fuel, perchloroethylene, pentachlorophenol, phenol, phosphorus, plutonium, polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), propylene glycol, phthalic anhydride, pyrethrins and pyrethroids, pyridine, radium, radon, RDX (cyclonite), selenium, silver, strontium, styrene, sulfur dioxide, sulfur trioxide, sulfuric acid, 1,1,2,2-tetrachloroethane, tetrachloroethylene, tetryl, thallium, thorium, tin, titanium tetrachloride, toluene, total petroleum hydrocarbons (TPH), toxaphene, trichlorobenzene, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene (TCE), 1,2,3-trichloropropane, 1,2,4-trimethylbenzene, 1,3,5-trinitrobenzene, 2,4,6-trinitrotoluene (TNT), uranium, vanadium, vinyl acetate, vinyl chloride, xylene and zinc.
The products of the invention can be applied in a variety of ways. Thus, the products may be formulated for specific end use applications such as by spraying, aerosolization, wiping, fogging or as a foam. In any event, an area to be decontaminated is treated by applying the product to or in the vicinity of the area using the product, generally at a temperature in the range of from about xe2x88x9250 to 300xc2x0 C., most usually at or about ambient temperature. If desired, a decontamination apparatus may be provided in the form of a container holding a quantity of the product and having an applicator operatively coupled with the container; such applicators may be selected from the group consisting of a spray nozzle, fog nozzle, foam nozzle, a wipe, a paste applicator and a gel applicator. In many instances, the product is pressurized or can be pressurized within the container typically at a level of from about 25-250 psi. A propellant may also be used such as those selected from the group consisting of N2, the noble gases, carbon dioxide, air, volatile hydrocarbons, hydrofluorocarbons, fluorocarbons and mixtures thereof.